Lamp socket



May 24, 1949. s.' E. BARr-ELsoN LAMP SOCKET Filed Aug. 30, 1946 (l'ttorlleg Patented May 24, 1949 LAMP SOCKET sten E. Bartelson, Ashland, N. J., assignnt'- Radio Corporation of America, a corporation of Delaware Application August 30, 1946, Serial'No. 694,038

4 Claims. (Cl. 173-328) This invention relates to lamp sockets and' particularly to improvements in sockets for prefocused electric lamps.

Sockets for pre-focused lamps are usually provided with a plurality of spring-biased pins which engage the base of the lamp and hold it in a position whereat the filament is in register with the optical system which the lamp is designed to serve. The removal of a lamp from such a socket against the biasing force of the retaining springs can be an extremely troublesome operation, particularly when the lamp is hot and is mounted in a motion picture projector or other crowded cabinet.

Accordingly, the principal object of the present invention is to provide an improved lamp socket of the type incorporating spring-actuated lampretaining pins, and one characterized by the provision of means for relieving the biasing force' on the said retaining pins, whereby to facilitate and Fig. 4 is fragmentary sectional view taken n the line IV-IV of Fig. 2. f

Referring particularly to Fig. 1, I designates generally a casting formed of metal, porcelain or other suitably rigid material which serves as a support for an optical system comprising a lens 2, an electric lamp 3 and a socket 4 which holds the lamp in a position whereat its horizontally disposed filament 5 is in register with the lens 2. The metal base of the lamp is oi' a conventional type and comprises a dependent tubular portion 6 which is provided, intermediate its ends, with an outwardly extending circular flange 'I having a number of circumferentially spaced slots la, 1b, 1c of tapered width arranged for the reception of a similar number of locking pins 8a, 8b, 8c which are mounted, in a manner later described, on the socket 4.

The socket comprises a hollow insulating .2 Y upper disc I0 is immovably secured to the to of the hollow pedestal 9 as by means of screws I2 and comprises a at conductive base upon which the tube flange l rests. The lower disc II, on the other hand, is supported for vertical movement within the socket pedestal upon the lower ends of the locking pins 8a, 8b, 8c. The said pins 8a etc. extend upwardly through suitably spaced clearance holes in the upper disc I0 and terminate thereabove in pin heads which limit the extent of the downward movement o the lower disc I I. The pins 8a, 8b, 8c, and hence the lower disc II to which the said pins are afllxed, are biased in the downward direction by means of springs I3a, I3b, I3c which are wrapped. respectively, about the said pins in the space between the upper and lower discs. A leaf spring I4 which terminates at a point adjacent to the center of the bore of the socket, beneath the lower disc II, comprises one terminal for the lamp lament 5 and a wire I5 secured t'o the upper disc I0 comprises the other filament lead.

The socket 4, as thus far described, is of more or less standard construction and the lamp 2 can be' mounted and locked therein by ventering the bayonet slots 1a, 1b, 'Ic over the similarly lettered retaining pins 8 and twisting the lamp to bring the reduced circular neck portions of the said slots into register with the pins so that the retaining force of the several springs I3a etc. is exerted upon the flange 1 of the lamp. The twisting force required to insert and to withdraw the lamp from its socket must be suflcient to overcome the biasing force applied to the retaining pins by the springs I3a etc. If the springs are still', as through long disuse, or the lamp is fragile or hot, it may be dimcult to apply the twisting force required to seat or unseat the lamp. This diillculty is overcome in accordance with the present invention by the provision of lever means for relieving the pins 8a, etc., and hence the tube flange l, of the force exerted thereon by the springs I3a, etc. during the period when the lamp is being seated in, or withdrawn from, the socket 4. In the illustrated embodiment of the invention the lever comprises a rotatable, rod-like piece I6 which spans the bore 9a of the socket pedestal 9, beneath the disc II to which the springs I3a etc. are attached, and a pair of lever arms I1 and I8 are afxed to the said rod and bear against the under side of the said disc II. One end of the rod I6 extends beyond the outer surface of the socket pedestal and terminates in a handle IIa which when pressed down, as indicated by the curved arrows in Fig.

3 1, causes the rod to rotate about its axis or fulcrum and to apply a lifting force to the disc II through th'e lever arms I1 and I8. Undesired axial movement of the lever is prevented by extending the lever arms I'I and I8, or one of them, through the rod-like member IB and, as shown in Fig. 4, placing the extended portion IIa within a slot |19, provided for the purpose, in the inner surface or bore 9a of the socket pedestal '9.

As shown in Fig. 3, raising the lower disc Il compresses the springs I3a, etc. against the upper, immovable disc l and relieves the biasing force on the retaining pins 8a, etc. With the retaining or locking force thus removed from the ange 'I the lamp can be easily removed from its socket.

It will now be apparent that the present in'V vention -provides an improved lock socket and one characterized by the provision of a simple,

inexpensive and trouble-free mechanism for vfacilitating the replacement oi' a lamp therein.

What is claimed is: f

1. A socket for an electrical device comprising a hollow pedestal, an apertured disc mounted on said pedestal, a washer provided with pins upwardly extending through said apertures and disposed within said pedestal, at least one spring positioned between said disc and washer for biasing the washer in a downward direction, e. cam acting directly on said washer for relieving the tension on said spring.

2. A socket for an electric lamp having a base, said socket comprising a hollow pedestal, a disc mounted on said pedestal, a oating washer disposed in said pedestal, the said washer carrying lamp retaining pins projecting from said washer in a position to engage said lamp base, springs associated with said pins and disposed between.

said disc and washer for biasing said pins into locking position with said base, a cam disposed under said washer and in direct contact there- 4 with i'or relieving the biasing force on said pins, and electrical terminals associated with said socket.

3. A socket for an electric lamp having a base. said socket comprising a hollow pedestal, a disc mounted on a pedestal, said disc having a central aperture adapted to receive said base, a floating washer disposed in said pedestal, the said washer carrying lamp retaining pins projecting from said washer in a position to engage said lamp base, springs associated with said pins and disposed between said disc and washer for biasing said pins into locking position with said base, a cam disposed under said washer and in direct contact therewith for relieving the biasing force on said pins, and electrical terminals associated with said socket.

4. A socket for an electric lamp having a base. said socket comprising a hollow pedestal, a disc mounted on said pedestal, a floating washer disposed in said pedestal, the said washer carrying lamp retaining pins projecting from said washer in a position to engage said lamp base, springs associated with said pins and disposed between said disc and washer for biasing said pins into locking position with said base, a cam disposed under said washer and in direct contact therewith for relieving the biasing torce on said pins, means for operating said cam, the said means extending to the external side of said pedestal, and electrical terminals associated with said socket.

SIEN E. BAR'I'EISON.

REFERENCES CITED The following references are oi' record in the ille of this patent:

UNITED. STATES PATENTS Number Name Date 298,143 Weston May 6, 1884 1,770,377 Wolfe July l5, 1930 1,796,038 Merle Mar. 10, 1931 2,110,133 Douglas Mar. 8, 1938 2,191,292 Spence, Jr. Feb. 20, 1940 2,426,424 Young Aug. 26, 1947 

